Rooney, who was the Association’s boss for 18 months up until 2004, said that if things go wrong for Roy, there could be conflict.

He said: “It’s a new, golden era for Irish soccer. Martin O’Neill is a very inspirational character, ever intellectual, well read, studied law. He’s a great man motivator.

“He’s a good coach and understands about putting a team together.

“Roy is a firebrand, very high standards...there’s potential for great opportunity and difficulty.

“The difficulty will be if there’s conflict, if there’s disagreement.

“I noticed in his interview [on Saturday when he was officially unveiled], Martin said he doesn’t expect to have to change Roy too much. Trying to change Roy at all will be a difficulty.

“He has that dark side when things are not right, his standards are so high. As a player he would demand that players get rest before a match.

“When they wouldn’t do what he wanted that’s when you saw the different side to him.

“He’s a very quiet individual, he’s courteous, he’s intelligent, well read himself, he reads books that you wouldn’t expect him to read.

“The biggest thing that upsets him so much is lack of standards in other individuals.”

The former FAI boss, who is also a barrister, was involved in announcing Roy’s return when he decided to play again for Ireland following his Saipan World Cup walkout in 2002.

He told RTE’s Marian Finucane that Roy is a divisive character and many fans didn’t want him back.

He added: “It was amazing how it was dealt with by members of the public. Some people just didn’t want him back. Post Saipan when he decided to come back and play.

“I remember one particular incident, I was doing a piece to camera for RTE and was announcing he was back.

“And a lot of people were delighted....but one individual on a push bike realised what was happening and he pulled up beside me live and said ‘that man shouldn’t even have a passport never mind a green jersey’.

“That’s how people were seeing it.”

But the former FAI boss is confident that Ireland will qualify for the next Euro Championships.

He said: “The next European Championships there’s going to be 24 teams as opposed to 16 so we have a very good chance of qualifying.

“The one thing I was a bit disappointed with is they [Keane and O’Neill] only got a two year contract; I’d have liked to see them get a four year contract to take us through to World Cup.